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Bash ssh for loop – env variable issue

When using a bash for loop and ssh’ing to multiple machines the hostname variable is not updated to be the name of the machine I’ve ssh’d into. What am I missing here? “A”, “B”, “C” are replaced with names of actual machines and the speech marks removed in…

Search and replace file content using shell script

I want to search and replace specific value in a file, here is the content of the file I want to replace DocumentRoot /var/www/html with DocumentRoot /var/www/html/centos I tried the following This is not working, can someone point me to the right direction. Thanks Answer The line you are trying to replace is…

Can resource attributes depend on file-presence?

I’m writing a module, that will provide for mirrored yum-repositories on our network. The single server will host the mirrors offering them to other hosts (and itself). I have a problem with the initial chicken-and-egg — the first download may not happen for a while, but, if I enable a new reposit…

Using the setuid bit in Linux

I have this C file: I compile it, set the UID and GID both to root and set the setuid bit, so that it looks like this: However when I call $ ./a.out I still get: What am I doing wrong? Answer The real user ID is still the user that called the program, but the effective user ID is

How to move window offscreen with wmctrl

I am trying to programmatically move a window so that it is partially on screen. For instance, clicking the VLC title bar and dragging it so that only half the window is visible works just fine. When I output the results of wmctrl -lG this works just fine: However, when I then move it back on screen and try a…